And he appointed certain of the Levites to minister before the
 ark of the Lord
 By singing the praises of God: 
 and to record;
 or bring to remembrance; to commemorate in a song the great and good things God had done for Israel as a people: 
 and to thank and praise the Lord God of Israel;
 for all his benefits, and the blessings of his goodness bestowed on them.